This is caused by a mismatch in OVS-CNI and CNAO versions D/S. I'm pushing a proper CNAO D/S now.
ovs-cni seems stable after installing a newer CNV version, where CNAO version is now v2.2.0-6 (ovs-cni-plugin & -marker version is still v2.2.0-3).
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHEA-2020:0307